Cell for ring-furnaces



J. D. BLACK;

CELL FOR RING FURNACES. APPLICATION FILED FEB. 9', 1920.

1,383,378. Patented y 5,1921.

3 SHEEIS-SHEET l- J. D. BLACK.

CELL FOR RING FURNACES. APPLICATION FILED FEB. 9. 1920.

1,383,378, Patented July 5, 1921.

3 SHEETS-.SHEEI 2.

J D BLACK CELL FOR RING FURNACES. APPLICATION nuzn FEB- 9. 1920. 1,383,378.

Patented July 5, 1921.

s SHEETSTSHEEI a.

UNITED STATES PATENT OFFICE.

JAMES D. BLACK, BAD-IN, NORTH CAROLINA, ASSIGNOR TO ALUMINUM COMPANY OF AMERICA, OF PITTSBURGH, PENNSYLVANIA, A. CORPORATION OF NEW JERSEY.

CELL FOR RING-FURNACES.

Specification of Letters Patent.

Patented July 5, 1921.

' Application filed February 9, 1920. SeriaLNo. 357,133.

To aZZ whom it may concern:

Be it known that 1, JAMES DUNO AN BLACK, a citizen of the United States, residing at Badin, in the county of Stanly and State of North Carolina, have invented certain new and useful Improvements in Cells for Ring-Furnaces, of which the following is a full, clear, and exact description.

This invention relates to so-called ring furnaces, for heating or baking articles of various kinds, as for example carbon electrodes for arc-lighting, for electric furnaces, for electrolytic processes, etc. In furnaces'of this type as usually constructed'at the present time, two parallel rows of heat ing chambers are constructed, preferably under ground and with the tops of the chambors flush with or extending slightly above the surface of the ground. When the fur nace is in operation all the chambers are in use in such manner that one or more chambers containing articles already heated or baked. (and still hot) are being cooled by air drawn in from the outside. This air, preheated by absorption of heat from the previously fired chambers, is dehvered to the next chamber and there supports combustion of the producer gas or other fuel with which the furnace is fired. From the furnace under fire the products of combustion pass through the next section or sections, and, in doing so, give up heat to the articles therein, thereby preheating such articles. When the articles in the chamber or section under fire are sufficiently heated or baked the supply of fuel is diverted therefrom to the next chamber, that is, the first of the chambers in which articles are being preheated. At the same time cooled articles from the first of the previously fired chambers are being removed, and fresh un heated or unbaked articles are being placed in the first empty chamber beyond those containing articles which are being preheated. In this way the fire proceeds down one row or series of chambers, then crosses over to the adjoining row, passes up the latter row to the end, and then over to the first row again, and so on. Hence the name ring furnace.

The present invention relates to furnaces of this general type, and its object is to provide an improved furnace in which d1stortion and breakage of the compartment parts is minimized and in which renewal and replacement of either vltal elements are facilitated. To this and other ends the lnventlon consists in the novel features of construction and combinations of elements hereinafter described.

Referring now to the drawings, in which a furnace embodying the present invention is illustrated Figure l is a fragmentary longitudinal sectional elevation on line BB of Fig. 2. Fig. 2 is a sectional plan view on the plane indicated approximately by the lines D, D of Fig.3.

Fig. 3 is a crosssection, on line A-A of Fig. 2. v

Fig. 4: is a diagrammatic longitudinal section illustrating the course of air and gases through the fiues of the furnace.

Referring now to Fig 4, X indicates a chamber which has been opened to permit the removal of heat-treated and thoroughly cooled articles, for instance carbon electrodes, hereinafter referred to simply as carbons. One or more succeeding chambers, for example three, indicated by a, b, 0, contain carbons that have been baked. Outside air enters the channeled or hollow walls and partitions of chamber X, flows through the similar walls, partitions and bottoms of chambers a, Z), c, absorbing more heat from said walls and bottom and from the freshly baked (and therefore highly heated) carbons in (l, and unites with the fuel gas burning under the cover of chamber 6. In the meantime, chamber X has been emptied and is being refilled; chamber a has been cooled. sufliciently to permit removal of its cover and the carbons in the chamber; and chamber 2', through which outside air was being admitted to chamber j and others beyond, has been loaded, so that the products of combustion from chamber f (now being fired) pass through the walls of chambers g, 71., and pass to the waste-gas flue. In like manner chamber 9 is next fired, chamber being opened for removal of carbons, chamber a being refilled, etc., the firing taking a progressive course down the first row, then across to and up the second, then across to and down the first again, continuously. In the procedure specifically outlined above (merely to illustrate and explain the operation of the furnace), nine chambers, for instance chambers X, a, b, h, constitute what may for convenience of de scription be termed a group. Of these thefirst (X) is open and is being unloaded i and, later, reloaded. The nextfour (a, Z), r 0, (Z) contain baked carbons whichare being cooled by air admitted through the open chamber (X). The next (e),is being fired, and the next three (7, g, k) are being preheated byproducts of combustion from c.

If, as is usually the case, there are in the entire furnace more chambers'than enough for a single-group, one or more other groups are in operation at the same time. Hence, it is customary to make the'total number of chambers an even multiple of the number of *chambers in". a; single group. Thus with i 1 each can be operated simultaneously. 1

four' groups of n1n\e more complete generaldescription of a com thirty-six chambers,

lete furnace will be found in the United tates applicationv of Bartley E. Broadwell, Serial No. 321,962, filed. January 22, 1918,

renewed September 5, 1919, now U. S. Patent No. 1,330,164 to whichreference is herei by made.

The chambers comprising the furnace,

which are closed by means of removable cov-r ers 10, are all exactly alike save for certain slight modifications. in the end chambers,

entailed by their positions, and which'need not bespecifically disclosed in this application: Each chamber'is divided by longitudinal wallsor partitions llinto cells 011.compartm'ents :(four in the present embodiment of the invention) These partitions, the V bottoms-of the chambers, the end walls 12,

and the side walls 13, are all hollow,'provid- "ing channels,-passages or fines, for the ase ousfuel, the air tosupport combustion, and the waste gases or productsof. combustion.

' Acrossthe top of each hollow end wall is ahorizontal partition 14, Figs. 1 and 3, 163v.

ing a'transverse passage 15 above it, which is' provided at itsinner end with-an inlet; opening 16 and at its outer end withan=out-- let 17; Thiszpassage or conduit 15 canbe' connected by meansof a connector 18 to a gas manifold 19 extending lengthwise of the furnace and supplied with combustible gas.

' The connecter 18 fits down upon the inlet 10 and uponthje appropriate one of a series of outlets 22- individual to the several cham- 'bers, andis removableso that it may be; I shifted from'ch'amber to chamber asthe fir- 1 ing progresses around the furna'ce in ringfashion as already mentioned. Such outlets as-arenot in use are closed by removablef covers? and the corresponding out-of -use inlet openings '16 of the passages 15*m'ay' be closed by'similar covers; Theioutlet' openings 17 may also be provided with covers. Along and just above the horizontalrpara tit'io'n 14 (Figs. 2 and 3) each end-wall 12 is formed with a series ofburner openings or V 5 ports 26, leadingfrom the adjacent transverse gaspassage 'or' conduit 15 which, it will be' remembered; receives combustible gas from the manifold 19 by of the let apertures 29. which areinverticalalinement with the burner-openings 26. Air ris-" ing-in the :up-flues 2 8 issues from the apertures 29 and supports the c'ombustion of the gas at the'burners 26. The down-fines, in the hollow longitudh nal partitions 11 and the hollow side walls 13, Figs. 1 and 3,far.e providedwith horizontal baffles 30, 31,pro-ducing tortuous pas combustion from the burning of jthe gas and air issuing from the apertures26 and" 29 respectively. The aforesaid hollow walls 12 are continued downwardly; into and through the hollow floor-or bottom of the furnace chamber, and thefiues 28 each comsages through which pass the products of l municate at the bottomjwiththe hollow bot-j I,

tom'of the next preceding chamber,- The J 5 chamber bottoms are providedwithtrahs? verse'openings 32 which connect the down 'fiues'fin'the partitions '11 and side walls13 with the passages in the hollow; bottoms. Between the partitions l l and side walls 13 the hollow bottom ofi thechamber is divided into longitudinal passages or firms 33 by longitudinal partitions 34. The products of combustion thereforei flow I downwardly between the bafies 30, 31, in" the down-fines I and side walls, laterally through the .aper-* tures 32 in the bottoms,and' thence longi tudinally through "the ducts "33 i to f the Verti cal .passagesor up-'fluesi2siin-the next-end v 'wa ll112.'; Rising in tlie latter walllwhich separates the chamber which is being fired,

froin the next, which latter contains carhens in process of being {pre-heated) the W products of combustion issue fronithe open-v ings 29 1n the end-wall last referred to,'jand thereafter pursue a course like that; already described, throughthe hollow walls, hot

tom, and partitionsoftlie'chamber.next sue- I ceeding the firing chamber; 7 For instance,

assuming that' chamber c, Fig. 4, isfbeing fired,;the products'of combustion or waste 1-"20 gasesfiowthrough passages or fines 28 and 33 of chambers g,jaiicl It in succession,

' It will be understood-that in. chambers 7", g,

and 7b the gas-inlet openings 16 "(not shown in Fig. 1) areclosed bytheir covers24.

Likewise, ithe oiitletfopenin-gs lfl of chain bers e, f, g and h are closed by covers (not shown) The outlet 17 o f'.chamber'i,lhow-. l" 7 ever, is connected'by asiphon-shaped pipe 7 or connector- 35 to'the; adjacent waste gas fiue36 running parallel to the adjacent side of the furnace. At a suitable point, say about the center, the flue 36 may be provided with an exhauster for drawing off the waste gases. V

As previously explained, the chambers cl, 0, Z) and a, in rear of firing chamber 6, contain carbons already fired and now being cooled,chamber (Z having been fired just.

before chamber e,while chamber X is empty, or is being emptied. Col d air enters chamber X and flows through openings 29, then down, under, and around the chambers a, b, c, d, absorbing heat from the walls, bottoms, and partitions of the chambers, thereby cooling the chambers and their contents. The air thus preheated finally reaches the firing chamber and issuesfrom the ports 29 to support combustion of the gas at the burners 26 as already described.

From the foregoing it will be seen that in each chamber the combustible gas issues from a transverse duct or passage in the top of the first transverse end-wall and burns forwardly in the combustion space or flue over the carbons piled in the cells into which the chamber is divided; it being understood, of course, that the carbons are covered with fire-brick dust or other inert non-combustible material to protect them from contact with the flame and possible injury by oxidation or otherwise. The pre heated air to support combustion rises through the up-fl-ue in the first hollow end wall and is discharged forwardly under the burning gas. Atthe far end of the chamber the products of combustion pass downwardly into the down-flues in the hollow side walls and longitudinal partitions, through the tortuous passages formed by the baifies in said walls and partitions. Reaclr ing the hollow bottom of the chamber the products of combustion flow laterally to right and left into the longitudinal passages or flues in said bottom, then longitudinally to the bottom of the up-fiue in the next transverse end-wall. The latter is the front end-wall of the next chamber, which, when the furnace is in operation,.contains unfired carbons. Passing up this wall the gases are discharged under the cover of the said chamber, which is the first chamber undergoing preheating, and pass down through the hollow partitions and side walls and through the bottom of the chamber, and so on, exactly as in the firing chamber, through as many chambers as contain unfired carbons. Finally the waste gases, most of whose heat having been given up to the carbon preheating chambers and contents, are delivered to the waste-gas flue. The air to support combustion in the firing chamber, as described, flows through the passages in the walls, partitions and bottoms of one or more chambers in rear of the firing chamber,

following like paths to those pursued by the products of combustion, already de scribed. These rear chambers are hot from previous firings and fired carbons, so that the air, taking heat therefrom, cools the chambers and their contents and is thereby preheated before it is discharged into t e firing chamber to support the combustion of the full gas delivered thereto.

It will be noted that the partitions 11 are subjected to intense heat when the particnlar chamber containing them is being fired. Then when the next succeeding chamber is being fired the partitions are subjected to a cooling draft of air. This repeated heating and cooling causes the said partitions to ex pand and contract respectively. If no provision were made to permit such expansion and contraction the partitions as well as other parts of the chamber would be subjected to stresses which would lead to distortion and fractures and thereby reduce the efiiciency and life of the furnace. In accordance with myinvention I provide an expansion joint between the partitions 11 and the end walls 12. While only one of such joints may be provided for each of said partitions I prefer to provide an expansion joint at each end of each partition. Referring more specifically to Fig. 2 it will be noted that each end wall is provided with a plurality of vertical slots each adapted to receive one end of a corresponding partition. Sufficient clearance is provided at 50 between the end walls 12 and the ends of partitions 11 to permit substantially unrestricted expansion of the latter when subjected to firing. The inner plates 13 of the side walls of the chambers are mounted in substantially the same wayas the partitions 11 as will be apparent on inspection of the drawings.

Besides the advantage set forth above it should be noted that the walls 12, partitions 11 and plates 13, which are most likely to break or become otherwise unfit for efficient use, may readily be withdrawn by lifting them vertically upward and new elements inserted. Replacements are thereby facilitated and the use of the furnace may be practically uninterrupted.

In order properly to assemble the chamher; 2'. 6., to insure that the various elements 11, 12 and 13 shall bear the proper relative position and alinement when assembled, I

prefer to employ the following process: Between each end of each of the members 11, 13 and its corresponding slot in the walls 12 (i. 6., in clearance spaces 50) I place spacing means which on subjection to the firing heat of the furnace, will be automatically removed from between the adjacent surfaces of the ends of members 11 and 13 and the slots in walls 12. Among other materials corrugated paper may be utilized for this purpose as combustion ofthis material will lead to its removal or disappearance when firing of the chamberstakes place. It will be understood that other materials may be employed such for example as substances whlch at normal temperatures are substanc tially solid but dissolve or volatilize when subjected to the firing temperature of the furnace.

' "What I claim is said" end walls, and removing said material bythe applicatlon of heat. 7

V 2. The process of assembling a furnace having end wall members and longitudinal partition members, which comprises interposing solid material between one set of said members and the ends'of the other set of members, and removing said material by the application of heat. 7

'3. A furnace comprising a plurality of cells,-means for conveying heating gas from eachofsa1dcells to another cell, each of signature; I

saidcells. havin --transverse' walls longitudinal side wal sand longitudinal parti tions and expansion joints between said transverse walls-and partitions.

4.=In a furnace of the type described,- in.

combination, a plurality ofchambers each having transverse walls and hollow longitudinal partitions, expansion joints between said partitions and walls, and means for conducting hot gases from the hollow'portions of the partitions dream of a plurality of chambers to the hollowportions of the partitions of a succeeding chamber.

5. In afurnaceof'the type described, in COIIlblIlftlllOIl aplurality of chambers each 7 having hollow transverse walls and longitudinal partitions,- expansion joi'nts between said partitions and walls, and means for conducting hot gases from the hollowpor-.

tions ofjeach'of a plurality ofsaid trans 'verse walls to the hollow portions ofsucceeding transverse walls.

In testimony whereof hereunto my 7 JAMEs 1). BL CK 7 

